add self-througt information about do not try to return a reference when you must an object
add self-througt information about do not try to return a reference when
you must an object

ASMlover/study,ASMlover/study,ASMlover/study,ASMlover/study,ASMlover/study,ASMlover/study,ASMlover/study,ASMlover/study,ASMlover/study